Oxygen humidifier



FIG. 1 shows a perspective view of our new design for an oxygen humidifier looking downwardly on the top thereof;

FIG. 2 shows a top plan view thereof;

FIG. 3 shows a side elevation view thereof looking from the left frontal side of the showing of FIG. 1; and,

FIG. 4 shows a bottom view thereof. 

The ornamental design for an oxygen humidifier, substantially as shown. 